/*-
 * Copyright (c) 2001 Alexey Zelkin <phantom@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */

#include <sys/types.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <monetary.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <errno_private.h>


/* internal flags */
#define	NEED_GROUPING		0x01	/* print digits grouped (default) */
#define	SIGN_POSN_USED		0x02	/* '+' or '(' usage flag */
#define	LOCALE_POSN			0x04	/* use locale defined +/- (default) */
#define	PARENTH_POSN		0x08	/* enclose negative amount in () */
#define	SUPRESS_CURR_SYMBOL	0x10	/* supress the currency from output */
#define	LEFT_JUSTIFY		0x20	/* left justify */
#define	USE_INTL_CURRENCY	0x40	/* use international currency symbol */
#define IS_NEGATIVE			0x80	/* is argument value negative ? */

/* internal macros */
#define PRINT(CH) do {								\
	if (dst >= s + maxsize) 						\
		goto e2big_error;							\
	*dst++ = CH;									\
} while (0)

#define PRINTS(STR) do {							\
	char *tmps = STR;								\
	while (*tmps != '\0')							\
		PRINT(*tmps++);								\
} while (0)

#define GET_NUMBER(VAR)	do {						\
	VAR = 0;										\
	while (isdigit((unsigned char)*fmt)) {			\
		if (VAR > INT_MAX / 10)						\
			goto e2big_error;						\
		VAR *= 10;									\
		VAR += *fmt - '0';							\
		if (VAR < 0)								\
			goto e2big_error;						\
		fmt++;										\
	}												\
} while (0)

#define GRPCPY(howmany) do {						\
	int i = howmany;								\
	while (i-- > 0) {								\
		avalue_size--;								\
		*--bufend = *(avalue+avalue_size+padded);	\
	}												\
} while (0)

#define GRPSEP do {									\
	*--bufend = thousands_sep;						\
	groups++;										\
} while (0)


extern struct lconv* localeconv_l(locale_t);

static ssize_t __strfmon(char*, size_t, struct lconv*, const char*, va_list ap);
static void __setup_vars(int, struct lconv*, char *, char *, char *, char **);
static int __calc_left_pad(int, struct lconv*, char *);
static char *__format_grouped_double(double, struct lconv*, int *, int, int, int);


ssize_t
strfmon(char *s, size_t maxsize, const char *format, ...)
{
	va_list ap;
	struct lconv* lc = localeconv();
	va_start(ap, format);
	return __strfmon(s, maxsize, lc, format, ap);
}


ssize_t
strfmon_l(char *s, size_t maxsize, locale_t locale, const char *format, ...)
{
	va_list ap;
	struct lconv* lc = localeconv_l(locale);
	va_start(ap, format);
	return __strfmon(s, maxsize, lc, format, ap);
}


static ssize_t
__strfmon(char *s, size_t maxsize, struct lconv* lc, const char *format, va_list ap)
{
	char 			*dst;		/* output destination pointer */
	const char 		*fmt;		/* current format poistion pointer */
	char			*asciivalue;	/* formatted double pointer */

	int		flags;		/* formatting options */
	int		pad_char;	/* padding character */
	int		pad_size;	/* pad size */
	int		width;		/* field width */
	int		left_prec;	/* left precision */
	int		right_prec;	/* right precision */
	double	value;		/* just value */
	char	space_char = ' '; /* space after currency */

	char	cs_precedes,	/* values gathered from struct lconv */
			sep_by_space,
			sign_posn,
			*signstr,
			*currency_symbol;

	char	*tmpptr;	/* temporary vars */
	int		sverrno;

	dst = s;
	fmt = format;
	asciivalue = NULL;
	currency_symbol = NULL;
	pad_size = 0;

	while (*fmt) {
		/* pass nonformating characters AS IS */
		if (*fmt != '%')
			goto literal;

		/* '%' found ! */

		/* "%%" mean just '%' */
		if (*(fmt+1) == '%') {
			fmt++;
	literal:
			PRINT(*fmt++);
			continue;
		}

		/* set up initial values */
		flags = (NEED_GROUPING|LOCALE_POSN);
		pad_char = ' ';		/* padding character is "space" */
		left_prec = -1;		/* no left precision specified */
		right_prec = -1;	/* no right precision specified */
		width = -1;		/* no width specified */
		value = 0;		/* we have no value to print now */

		/* Flags */
		while (1) {
			switch (*++fmt) {
				case '=':	/* fill character */
					pad_char = *++fmt;
					if (pad_char == '\0')
						goto format_error;
					continue;
				case '^':	/* not group currency  */
					flags &= ~(NEED_GROUPING);
					continue;
				case '+':	/* use locale defined signs */
					if (flags & SIGN_POSN_USED)
						goto format_error;
					flags |= (SIGN_POSN_USED|LOCALE_POSN);
					continue;
				case '(':	/* enclose negatives with () */
					if (flags & SIGN_POSN_USED)
						goto format_error;
					flags |= (SIGN_POSN_USED|PARENTH_POSN);
					continue;
				case '!':	/* suppress currency symbol */
					flags |= SUPRESS_CURR_SYMBOL;
					continue;
				case '-':	/* alignment (left)  */
					flags |= LEFT_JUSTIFY;
					continue;
				default:
					break;
			}
			break;
		}

		/* field Width */
		if (isdigit((unsigned char)*fmt)) {
			GET_NUMBER(width);
			/* Do we have enough space to put number with
			 * required width ?
			 */
			if ((unsigned int)width >= maxsize - (dst - s))
				goto e2big_error;
		}

		/* Left precision */
		if (*fmt == '#') {
			if (!isdigit((unsigned char)*++fmt))
				goto format_error;
			GET_NUMBER(left_prec);
			if ((unsigned int)left_prec >= maxsize - (dst - s))
				goto e2big_error;
		}

		/* Right precision */
		if (*fmt == '.') {
			if (!isdigit((unsigned char)*++fmt))
				goto format_error;
			GET_NUMBER(right_prec);
			if ((unsigned int)right_prec >= maxsize - (dst - s) - left_prec)
				goto e2big_error;
		}

		/* Conversion Characters */
		switch (*fmt++) {
			case 'i':	/* use internaltion currency format */
				flags |= USE_INTL_CURRENCY;
				break;
			case 'n':	/* use national currency format */
				flags &= ~(USE_INTL_CURRENCY);
				break;
			default:	/* required character is missing or
						   premature EOS */
				goto format_error;
		}

		if (currency_symbol != NULL)
			free(currency_symbol);
		if (flags & USE_INTL_CURRENCY) {
			currency_symbol = strdup(lc->int_curr_symbol);
			if (currency_symbol != NULL) {
				space_char = currency_symbol[3];
				currency_symbol[3] = '\0';
			}
		} else
			currency_symbol = strdup(lc->currency_symbol);

		if (currency_symbol == NULL)
			goto end_error;			/* ENOMEM. */

		/* value itself */
		value = va_arg(ap, double);

		/* detect sign */
		if (value < 0) {
			flags |= IS_NEGATIVE;
			value = -value;
		}

		/* fill left_prec with amount of padding chars */
		if (left_prec >= 0) {
			pad_size = __calc_left_pad((flags ^ IS_NEGATIVE), lc,
				currency_symbol) - __calc_left_pad(flags, lc, currency_symbol);
			if (pad_size < 0)
				pad_size = 0;
		}

		if (asciivalue != NULL)
			free(asciivalue);
		asciivalue = __format_grouped_double(value, lc, &flags, left_prec,
			right_prec, pad_char);
		if (asciivalue == NULL)
			goto end_error;		/* errno already set     */
								/* to ENOMEM by malloc() */

		/* set some variables for later use */
		__setup_vars(flags, lc, &cs_precedes, &sep_by_space, &sign_posn, &signstr);

		/*
		 * Description of some LC_MONETARY's values:
		 *
		 * p_cs_precedes & n_cs_precedes
		 *
		 * = 1 - $currency_symbol precedes the value
		 *       for a monetary quantity with a non-negative value
		 * = 0 - symbol succeeds the value
		 *
		 * p_sep_by_space & n_sep_by_space
		 *
		 * = 0 - no space separates $currency_symbol
		 *       from the value for a monetary quantity with a
		 *       non-negative value
		 * = 1 - space separates the symbol from the value
		 * = 2 - space separates the symbol and the sign string,
		 *       if adjacent.
		 *
		 * p_sign_posn & n_sign_posn
		 *
		 * = 0 - parentheses enclose the quantity and the
		 *       $currency_symbol
		 * = 1 - the sign string precedes the quantity and the
		 *       $currency_symbol
		 * = 2 - the sign string succeeds the quantity and the
		 *       $currency_symbol
		 * = 3 - the sign string precedes the $currency_symbol
		 * = 4 - the sign string succeeds the $currency_symbol
		 *
		 */

		tmpptr = dst;

		while (pad_size-- > 0)
			PRINT(' ');

		if (sign_posn == 0 && (flags & IS_NEGATIVE))
			PRINT('(');

		if (cs_precedes == 1) {
			if (sign_posn == 1 || sign_posn == 3) {
				PRINTS(signstr);
				if (sep_by_space == 2)		/* XXX: ? */
					PRINT(' ');
			}

			if (!(flags & SUPRESS_CURR_SYMBOL)) {
				PRINTS(currency_symbol);

				if (sign_posn == 4) {
					if (sep_by_space == 2)
						PRINT(space_char);
					PRINTS(signstr);
					if (sep_by_space == 1)
						PRINT(' ');
				} else if (sep_by_space == 1)
					PRINT(space_char);
			}
		} else if (sign_posn == 1)
			PRINTS(signstr);

		PRINTS(asciivalue);

		if (cs_precedes == 0) {
			if (sign_posn == 3) {
				if (sep_by_space == 1)
					PRINT(' ');
				PRINTS(signstr);
			}

			if (!(flags & SUPRESS_CURR_SYMBOL)) {
				if ((sign_posn == 3 && sep_by_space == 2)
				    || (sep_by_space == 1
				    	&& (sign_posn == 0
				    		|| sign_posn == 1
				    		|| sign_posn == 2
				    		|| sign_posn == 4)))
					PRINT(space_char);
				PRINTS(currency_symbol); /* XXX: len */
				if (sign_posn == 4) {
					if (sep_by_space == 2)
						PRINT(' ');
					PRINTS(signstr);
				}
			}
		}

		if (sign_posn == 2) {
			if (sep_by_space == 2)
				PRINT(' ');
			PRINTS(signstr);
		}

		if (sign_posn == 0 && (flags & IS_NEGATIVE))
			PRINT(')');

		if (dst - tmpptr < width) {
			if (flags & LEFT_JUSTIFY) {
				while (dst - tmpptr < width)
					PRINT(' ');
			} else {
				pad_size = dst - tmpptr;
				memmove(tmpptr + width - pad_size, tmpptr, pad_size);
				memset(tmpptr, ' ', width - pad_size);
				dst += width - pad_size;
			}
		}
	}

	PRINT('\0');
	va_end(ap);
	free(asciivalue);
	free(currency_symbol);
	return dst - s - 1;	/* return size of put data except trailing '\0' */

e2big_error:
	__set_errno(E2BIG);
	goto end_error;

format_error:
	__set_errno(EINVAL);

end_error:
	sverrno = errno;
	if (asciivalue != NULL)
		free(asciivalue);
	if (currency_symbol != NULL)
		free(currency_symbol);
	__set_errno(sverrno);
	va_end(ap);
	return -1;
}


static void
__setup_vars(int flags, struct lconv* lc, char *cs_precedes, char *sep_by_space, char *sign_posn,
	char **signstr)
{
	if ((flags & IS_NEGATIVE) && (flags & USE_INTL_CURRENCY)) {
		*cs_precedes = lc->int_n_cs_precedes;
		*sep_by_space = lc->int_n_sep_by_space;
		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_n_sign_posn;
		*signstr = (lc->negative_sign[0] == '\0') ? "-" : lc->negative_sign;
	} else if (flags & USE_INTL_CURRENCY) {
		*cs_precedes = lc->int_p_cs_precedes;
		*sep_by_space = lc->int_p_sep_by_space;
		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->int_p_sign_posn;
		*signstr = lc->positive_sign;
	} else if (flags & IS_NEGATIVE) {
		*cs_precedes = lc->n_cs_precedes;
		*sep_by_space = lc->n_sep_by_space;
		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->n_sign_posn;
		*signstr = (lc->negative_sign[0] == '\0') ? "-" : lc->negative_sign;
	} else {
		*cs_precedes = lc->p_cs_precedes;
		*sep_by_space = lc->p_sep_by_space;
		*sign_posn = (flags & PARENTH_POSN) ? 0 : lc->p_sign_posn;
		*signstr = lc->positive_sign;
	}

	/* Set defult values for unspecified information. */
	if (*cs_precedes != 0)
		*cs_precedes = 1;
	if (*sep_by_space == CHAR_MAX)
		*sep_by_space = 0;
	if (*sign_posn == CHAR_MAX)
		*sign_posn = 0;
}


static int
__calc_left_pad(int flags, struct lconv* lc, char *cur_symb)
{
	char cs_precedes, sep_by_space, sign_posn, *signstr;
	int left_chars = 0;

	__setup_vars(flags, lc, &cs_precedes, &sep_by_space, &sign_posn, &signstr);

	if (cs_precedes != 0) {
		left_chars += strlen(cur_symb);
		if (sep_by_space != 0)
			left_chars++;
	}

	switch (sign_posn) {
		case 1:
			left_chars += strlen(signstr);
			break;
		case 3:
		case 4:
			if (cs_precedes != 0)
				left_chars += strlen(signstr);
	}
	return left_chars;
}


static int
get_groups(int size, char *grouping)
{
	int	chars = 0;

	if (*grouping == CHAR_MAX || *grouping <= 0)	/* no grouping ? */
		return 0;

	while (size > (int)*grouping) {
		chars++;
		size -= (int)*grouping++;
		/* no more grouping ? */
		if (*grouping == CHAR_MAX)
			break;
		/* rest grouping with same value ? */
		if (*grouping == 0) {
			chars += (size - 1) / *(grouping - 1);
			break;
		}
	}
	return chars;
}


/* convert double to ASCII */
static char *
__format_grouped_double(double value, struct lconv* lc, int *flags, int left_prec, int right_prec,
	int pad_char)
{
	char	*rslt;
	char	*avalue;
	int		avalue_size;
	char	fmt[32];

	size_t	bufsize;
	char	*bufend;

	int		padded;

	char	*grouping;
	char	decimal_point;
	char	thousands_sep;

	int groups = 0;

	grouping = lc->mon_grouping;
	decimal_point = *lc->mon_decimal_point;
	if (decimal_point == '\0')
		decimal_point = *lc->decimal_point;
	thousands_sep = *lc->mon_thousands_sep;
	if (thousands_sep == '\0')
		thousands_sep = *lc->thousands_sep;

	/* fill left_prec with default value */
	if (left_prec == -1)
		left_prec = 0;

	/* fill right_prec with default value */
	if (right_prec == -1) {
		if (*flags & USE_INTL_CURRENCY)
			right_prec = lc->int_frac_digits;
		else
			right_prec = lc->frac_digits;

		if (right_prec == CHAR_MAX)	/* POSIX locale ? */
			right_prec = 2;
	}

	if (*flags & NEED_GROUPING)
		left_prec += get_groups(left_prec, grouping);

	/* convert to string */
	snprintf(fmt, sizeof(fmt), "%%%d.%df", left_prec + right_prec + 1,
		right_prec);
	avalue_size = asprintf(&avalue, fmt, value);
	if (avalue_size < 0)
		return NULL;

	/* make sure that we've enough space for result string */
	bufsize = strlen(avalue) * 2 + 1;
	rslt = calloc(1, bufsize);
	if (rslt == NULL) {
		free(avalue);
		return NULL;
	}
	bufend = rslt + bufsize - 1;	/* reserve space for trailing '\0' */

	/* skip spaces at beggining */
	padded = 0;
	while (avalue[padded] == ' ') {
		padded++;
		avalue_size--;
	}

	if (right_prec > 0) {
		bufend -= right_prec;
		memcpy(bufend, avalue + avalue_size + padded - right_prec, right_prec);
		*--bufend = decimal_point;
		avalue_size -= right_prec + 1;
	}

	if ((*flags & NEED_GROUPING) && *grouping != CHAR_MAX && *grouping > 0
		&& thousands_sep != '\0') {
		while (avalue_size > (int)*grouping) {
			GRPCPY(*grouping);
			GRPSEP;
			grouping++;

			/* no more grouping ? */
			if (*grouping == CHAR_MAX)
				break;

			/* rest grouping with same value ? */
			if (*grouping == 0) {
				grouping--;
				while (avalue_size > *grouping) {
					GRPCPY(*grouping);
					GRPSEP;
				}
			}
		}
		if (avalue_size != 0)
			GRPCPY(avalue_size);
		padded -= groups;
	} else {
		bufend -= avalue_size;
		memcpy(bufend, avalue + padded, avalue_size);
		if (right_prec == 0)
			padded--;	/* decrease assumed $decimal_point */
	}

	/* do padding with pad_char */
	if (padded > 0) {
		bufend -= padded;
		memset(bufend, pad_char, padded);
	}

	bufsize = bufsize - (bufend - rslt) + 1;
	memmove(rslt, bufend, bufsize);
	free(avalue);

	return rslt;
}
